Looking for a particular hanger type

[nwoods]

I am looking for a hanger that can slip over the top of my Jeep tailgate (U-shaped hook at the top), with a bent L lower leg, that I can mount a tray onto. ideally, the hook can fold or detach from the tray for easy storage.

Basically, I want a tray sort of like the Off Road Trail tools tray, but one that just hangs on the back temporarily. I am having a heck of a time finding the right sort of hanger. Any ideas?

An example of what I am describing would be the sort of hook that fits over the top of a door...like the indoor basketball hoops you had in college

 

[UK4X4]

Home depot

1 off 3' long 1" X 3/16" aluminum or steel bar
1 off hammer
1 off drill to attach table
1 off 2' length of hose pipe cut in 2 to slip over the curved upper hooks
4 off 1/4" countersunk machine screws
4 off wing nuts